>> a self-described baseball fan but not a card collector, karl did some research and realized what he had. he contacted heritage auctions out of dallas, texas to come in and authenticate the collection. >> when they called us up and said, carl, this is one of the most significant finds of baseball cards ever, i was like, no, it's just baseball cards. no. in this particular series, in this particular card, in this condition, some of them are mint condition. it just blows everybody away. >> the collection contains hundreds of cards but there are 27 in particular that could fetch millions. they're from a rare 1910 e-98 series. carl compares it to finding a mona lisa in the attic. >> experts call it. >> cardboard gold. if there was such a thing, this is it. >> as you can imagine, the cards are under lock and key once again in solitude awaiting auction. an auction made possible by carl's aunt.